Articulation features for ultrasonic surgical instrument

ABSTRACT

A surgical apparatus comprises a body, an ultrasonic transducer, a shaft, an acoustic waveguide, an articulation section, an end effector, and an articulation drive assembly. The ultrasonic transducer is operable to convert electrical power into ultrasonic vibrations. The shaft couples the end effector and the body together. The acoustic waveguide is coupled with the transducer. The articulation section includes a collar that is located distal to a nodal portion of the waveguide and is operable to deflect the end effector away from the longitudinal axis. The end effector comprises an ultrasonic blade in acoustic communication with the ultrasonic transducer. The articulation drive assembly is operable to drive articulation of the articulation section. The articulation drive assembly comprises at least one translating articulation driver coupled with the collar. The ultrasonic blade is operable to deliver ultrasonic vibrations to tissue even when the articulation section is in an articulated state.

BACKGROUND

A variety of surgical instruments include an end effector having a bladeelement that vibrates at ultrasonic frequencies to cut and/or sealtissue (e.g., by denaturing proteins in tissue cells). These instrumentsinclude piezoelectric elements that convert electrical power intoultrasonic vibrations, which are communicated along an acousticwaveguide to the blade element. The precision of cutting and coagulationmay be controlled by the surgeon's technique and adjusting the powerlevel, blade edge, tissue traction and blade pressure.

Examples of ultrasonic surgical instruments include the HARMONIC ACE®Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONICFOCUS® Ultrasonic Shears, and the HARMONIC SYNERGY® Ultrasonic Blades,all by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. Further examplesof such devices and related concepts are disclosed in U.S. Pat. No.5,322,055, entitled “Clamp Coagulator/Cutting System for UltrasonicSurgical Instruments,” issued Jun. 21, 1994, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,873,873, entitled“Ultrasonic Clamp Coagulator Apparatus Having Improved Clamp Mechanism,”issued Feb. 23, 1999, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 5,980,510, entitled “Ultrasonic ClampCoagulator Apparatus Having Improved Clamp Arm Pivot Mount,” filed Oct.10, 1997, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,325,811, entitled “Blades with Functional BalanceAsymmetries for use with Ultrasonic Surgical Instruments,” issued Dec.4, 2001, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,773,444, entitled “Blades with Functional BalanceAsymmetries for Use with Ultrasonic Surgical Instruments,” issued Aug.10, 2004, the disclosure of which is incorporated by reference herein;and U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” issued Aug. 31, 2004,the disclosure of which is incorporated by reference herein.

Still further examples of ultrasonic surgical instruments are disclosedin U.S. Pub. No. 2006/0079874, entitled “Tissue Pad for Use with anUltrasonic Surgical Instrument,” published Apr. 13, 2006, the disclosureof which is incorporated by reference herein; U.S. Pub. No.2007/0191713, entitled “Ultrasonic Device for Cutting and Coagulating,”published Aug. 16, 2007, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2007/0282333, entitled “UltrasonicWaveguide and Blade,” published Dec. 6, 2007, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2008/0200940, entitled“Ultrasonic Device for Cutting and Coagulating,” published Aug. 21,2008, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2009/0105750, entitled “Ergonomic Surgical Instruments,”published Apr. 23, 2009, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2010/0069940, entitled “UltrasonicDevice for Fingertip Control,” published Mar. 18, 2010, the disclosureof which is incorporated by reference herein; and U.S. Pub. No.2011/0015660, entitled “Rotating Transducer Mount for UltrasonicSurgical Instruments,” published Jan. 20, 2011, the disclosure of whichis incorporated by reference herein; and U.S. Pub. No. 2012/0029546,entitled “Ultrasonic Surgical Instrument Blades,” published Feb. 2,2012, the disclosure of which is incorporated by reference herein.

Some of ultrasonic surgical instruments may include a cordlesstransducer such as that disclosed in U.S. Pub. No. 2012/0112687,entitled “Recharge System for Medical Devices,” published May 10, 2012,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2012/0116265, entitled “Surgical Instrument with Charging Devices,”published May 10, 2012, the disclosure of which is incorporated byreference herein; and/or U.S. Pat. App. No. 61/410,603, filed Nov. 5,2010, entitled “Energy-Based Surgical Instruments,” the disclosure ofwhich is incorporated by reference herein.

Additionally, some ultrasonic surgical instruments may include anarticulating shaft section. Examples of such ultrasonic surgicalinstruments are disclosed in U.S. patent application Ser. No.13/538,588, filed Jun. 29, 2012, entitled “Surgical Instruments withArticulating Shafts,” the disclosure of which is incorporated byreference herein; and U.S. patent application Ser. No. 13/657,553, filedOct. 22, 2012, entitled “Flexible Harmonic Waveguides/Blades forSurgical Instruments,” the disclosure of which is incorporated byreference herein.

While several surgical instruments and systems have been made and used,it is believed that no one prior to the inventors has made or used theinvention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a side elevational view of an exemplary ultrasonicsurgical instrument;

FIG. 2 depicts a perspective view of a shaft assembly and end effectorof the surgical instrument of FIG. 1;

FIG. 3 depicts an exploded perspective view of the shaft assembly andend effector of FIG. 2;

FIG. 4 depicts a cross-sectional side view of the shaft assembly and endeffector of FIG. 2;

FIG. 5 depicts a perspective view of components of the shaft assemblyand end effector of FIG. 2;

FIG. 6A depicts a cross-sectional view of the components of FIG. 5,taken along line 6-6 of FIG. 4, in a straight configuration;

FIG. 6B depicts a cross-sectional view of the components of FIG. 5,taken along line 6-6 of FIG. 4, in a bent configuration;

FIG. 7 depicts another cross-sectional view of the components of FIG. 5,taken along line 7-7 of FIG. 4;

FIG. 8 depicts a perspective view of an exemplary mechanism for drivingarticulation of the shaft assembly of FIG. 2;

FIG. 9 depicts a side elevational view of the mechanism of FIG. 8;

FIG. 10A depicts a top plan view of the mechanism of FIG. 8, with adrive gear in a first rotational position;

FIG. 10B depicts a top plan view of the mechanism of FIG. 8, with thedrive gear in a second rotational position;

FIG. 11 depicts a perspective view of an exemplary alternative mechanismfor driving articulation of the shaft assembly of FIG. 2;

FIG. 12A depicts a cross-sectional view of the mechanism of FIG. 11,with a rotation knob in a first longitudinal position and disengagedfrom an articulation driver;

FIG. 12B depicts a cross-sectional view of the mechanism of FIG. 11,with the rotation knob in a second longitudinal position and engagedwith the articulation driver in a first rotational position;

FIG. 12C depicts a cross-sectional view of the mechanism of FIG. 11,with the rotation knob in the second longitudinal position and engagedwith the articulation driver in a second rotational position;

FIG. 13A depicts a side elevational view of another exemplaryalternative mechanism for driving articulation of the shaft assembly ofFIG. 2, in a first operational state;

FIG. 13B depicts a side elevational view of the mechanism of FIG. 13A,in a second operational state;

FIG. 14 depicts a top view of yet another exemplary alternativemechanism for driving articulation of the shaft assembly of FIG. 2;

FIG. 15A depicts a perspective view of the mechanism of FIG. 14, with apair of gear racks in a first longitudinal position;

FIG. 15B depicts a perspective view of the mechanism of FIG. 14, withthe pair of gear racks in a second longitudinal position;

FIG. 16A depicts a top view of yet another exemplary alternativemechanism for driving articulation of the shaft assembly of FIG. 2, witha drive gear in a first rotational position;

FIG. 16B depicts a top plan view of the mechanism of FIG. 16A, with thedrive gear in a second rotational position;

FIG. 17A depicts a side elevational view of yet another exemplaryalternative mechanism for driving articulation of the shaft assembly ofFIG. 2, with a drive arm in a first longitudinal position;

FIG. 17B depicts a side elevational view of the mechanism of FIG. 17A,with the drive arm in a second longitudinal position;

FIG. 18A depicts a top plan view of an exemplary alternativearticulation section in a bent configuration;

FIG. 18B depicts a top plan view of the articulation section of FIG. 18Ain a straight configuration;

FIG. 19 depicts a perspective view of another exemplary articulationsection;

FIG. 20A depicts a cross-sectional side view of the articulation sectionof FIG. 19 in a straight configuration;

FIG. 20B depicts a cross-sectional side view of the articulation sectionof FIG. 19 in a bent configuration;

FIG. 21 depicts a perspective view of yet another exemplary articulationsection and end effector;

FIG. 22 depicts a perspective view of the articulation section and endeffector of FIG. 21, with an outer sheath removed;

FIG. 23 depicts a cross-sectional view of the articulation section andend effector of FIG. 21, with the articulation section in a straightconfiguration;

FIG. 24 depicts a cross-sectional view of the articulation section andend effector of FIG. 21, with the articulation section in a bentconfiguration;

FIG. 25 depicts a top plan view of the articulation section and endeffector of FIG. 21, with the articulation section in a bentconfiguration;

FIG. 26 depicts an exploded perspective view of the articulation sectionand end effector of FIG. 21;

FIG. 27 depicts a cross-sectional end view of the articulation sectionof FIG. 21;

FIG. 28 depicts a perspective view of the articulation section and endeffector of FIG. 21 with an exemplary alternative outer sheath;

FIG. 29 depicts a perspective view of the articulation section and endeffector of FIG. 21 with another exemplary alternative outer sheath;

FIG. 30 depicts a cross-sectional end view of an exemplary alternativeconfiguration of the articulation section of FIG. 21;

FIG. 31 depicts a cross-sectional end view of another exemplaryalternative configuration of the articulation section of FIG. 21;

FIG. 32 depicts a cross-sectional side view of an exemplary alternativearticulation section with a clamp arm closure sheath, with the clamp armin an open position and the articulation section in a straightconfiguration;

FIG. 33 depicts a cross-sectional side view of the articulation sectionof FIG. 32, with the clamp arm in a closed position and the articulationsection in a straight configuration;

FIG. 34 depicts a cross-sectional side view of the articulation sectionof FIG. 32, with the clamp arm in a closed position and the articulationsection in a bent configuration;

FIG. 35A depicts a top plan view of yet another exemplary articulationsection in a straight configuration;

FIG. 35B depicts a top plan view of the articulation section of FIG. 35Ain a first bent configuration;

FIG. 35C depicts a top plan view of the articulation section of FIG. 35Ain a second bent configuration;

FIG. 36 depicts a perspective view of another exemplary articulationsection;

FIG. 37 depicts an exploded perspective view of the articulation sectionof FIG. 36;

FIG. 38 depicts a perspective view of the distal portion of thewaveguide that extends through the articulation section of FIG. 36;

FIG. 39 depicts a perspective view of a pair of ribbed body portions ofthe articulation section of FIG. 36;

FIG. 40 depicts a perspective view of a distal collar of thearticulation section of FIG. 36;

FIG. 41 depicts a top elevational view of the articulation section ofFIG. 36;

FIG. 42 depicts a top cross-sectional view of the articulation sectionof FIG. 36;

FIG. 43A depicts a perspective view of an exemplary alternative shaftassembly with a reusable portion and a disposable portion disconnected;

FIG. 43B depicts a perspective view of the shaft assembly of FIG. 43Awith the reusable portion and the disposable portion connected;

FIG. 44A depicts a cross-sectional side view of the shaft assembly ofFIG. 43A with the reusable portion and the disposable portiondisconnected; and

FIG. 44B depicts a cross-sectional side view of the shaft assembly ofFIG. 43A with the reusable portion and the disposable portion connected.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a human or robotic operator of the surgicalinstrument. The term “proximal” refers the position of an element closerto the human or robotic operator of the surgical instrument and furtheraway from the surgical end effector of the surgical instrument. The term“distal” refers to the position of an element closer to the surgical endeffector of the surgical instrument and further away from the human orrobotic operator of the surgical instrument.

I. Exemplary Ultrasonic Surgical Instrument

FIG. 1 illustrates an exemplary ultrasonic surgical instrument (10). Atleast part of instrument (10) may be constructed and operable inaccordance with at least some of the teachings of U.S. Pat. No.5,322,055; U.S. Pat. No. 5,873,873; U.S. Pat. No. 5,980,510; U.S. Pat.No. 6,325,811; U.S. Pat. No. 6,773,444; U.S. Pat. No. 6,783,524; U.S.Pub. No. 2006/0079874; U.S. Pub. No. 2007/0191713; U.S. Pub. No.2007/0282333; U.S. Pub. No. 2008/0200940; U.S. Pub. No. 2009/0105750;U.S. Pub. No. 2010/0069940; U.S. Pub. No. 2011/0015660; U.S. Pub. No.2012/0112687; U.S. Pub. No. 2012/0116265; U.S. patent application Ser.No. 13/538,588; U.S. patent application Ser. No. 13/657,553; and/or U.S.Pat. App. No. 61/410,603. The disclosures of each of the foregoingpatents, publications, and applications are incorporated by referenceherein. As described therein and as will be described in greater detailbelow, instrument (10) is operable to cut tissue and seal or weld tissue(e.g., a blood vessel, etc.) substantially simultaneously. It shouldalso be understood that instrument (10) may have various structural andfunctional similarities with the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades. Furthermore, instrument(10) may have various structural and functional similarities with thedevices taught in any of the other references that are cited andincorporated by reference herein.

To the extent that there is some degree of overlap between the teachingsof the references cited herein, the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades, and the followingteachings relating to instrument (10), there is no intent for any of thedescription herein to be presumed as admitted prior art. Severalteachings herein will in fact go beyond the scope of the teachings ofthe references cited herein and the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and the HARMONIC SYNERGY® Ultrasonic Blades.

Instrument (10) of the present example comprises a handle assembly (20),a shaft assembly (30), and an end effector (40). Handle assembly (20)comprises a body (22) including a pistol grip (24) and a pair of buttons(26). Handle assembly (20) also includes a trigger (28) that ispivotable toward and away from pistol grip (24). It should beunderstood, however, that various other suitable configurations may beused, including but not limited to a scissor grip configuration. Endeffector (40) includes an ultrasonic blade (160) and a pivoting clamparm (44). Clamp arm (44) is coupled with trigger (28) such that clamparm (44) is pivotable toward ultrasonic blade (160) in response topivoting of trigger (28) toward pistol grip (24); and such that clamparm (44) is pivotable away from ultrasonic blade (160) in response topivoting of trigger (28) away from pistol grip (24). Various suitableways in which clamp arm (44) may be coupled with trigger (28) will beapparent to those of ordinary skill in the art in view of the teachingsherein. In some versions, one or more resilient members are used to biasclamp arm (44) and/or trigger (28) to the open position shown in FIG. 1.

An ultrasonic transducer assembly (12) extends proximally from body (22)of handle assembly (20). Transducer assembly (12) is coupled with agenerator (16) via a cable (14). Transducer assembly (12) receiveselectrical power from generator (16) and converts that power intoultrasonic vibrations through piezoelectric principles. Generator (16)may include a power source and control module that is configured toprovide a power profile to transducer assembly (12) that is particularlysuited for the generation of ultrasonic vibrations through transducerassembly (12). By way of example only, generator (16) may comprise a GEN300 sold by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. In additionor in the alternative, generator (16) may be constructed in accordancewith at least some of the teachings of U.S. Pub. No. 2011/0087212,entitled “Surgical Generator for Ultrasonic and ElectrosurgicalDevices,” published Apr. 14, 2011, the disclosure of which isincorporated by reference herein. It should also be understood that atleast some of the functionality of generator (16) may be integrated intohandle assembly (20), and that handle assembly (20) may even include abattery or other on-board power source such that cable (14) is omitted.Still other suitable forms that generator (16) may take, as well asvarious features and operabilities that generator (16) may provide, willbe apparent to those of ordinary skill in the art in view of theteachings herein.

A. Exemplary End Effector and Acoustic Drivetrain

As best seen in FIGS. 2-4, end effector (40) of the present examplecomprises clamp arm (44) and ultrasonic blade (160). Clamp arm (44)includes a clamp pad (46) that is secured to the underside of clamp arm(44), facing blade (160). Clamp arm (44) is pivotally secured to adistally projecting tongue (43) of a first ribbed body portion (132),which forms part of an articulation section (130) as will be describedin greater detail below. Clamp arm (44) is operable to selectively pivottoward and away from blade (160) to selectively clamp tissue betweenclamp arm (44) and blade (160). A pair of arms (156) extend transverselyto clamp arm (44) and are secured to a pin (170) that extends laterallybetween arms (156). A rod (174) is secured to pin (170). Rod (174)extends distally from a closure tube (176) and is unitarily secured toclosure tube (176). Closure tube (176) is operable to translatelongitudinally relative to articulation section (130) to selectivelypivot clamp arm (44) toward and away from blade (160). In particular,closure tube (176) is coupled with trigger (28) such that clamp arm (44)pivots toward blade (160) in response to pivoting of trigger (28) towardpistol grip (24); and such that clamp arm (44) pivots away from blade(160) in response to pivoting of trigger (28) away from pistol grip(24). A leaf spring (172) biases clamp arm (44) to the open position inthe present example, such that (at least in some instances) the operatormay effectively open clamp arm (44) by releasing a grip on trigger (28).

Blade (160) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being clamped between clamp pad (46) andblade (160). Blade (160) is positioned at the distal end of an acousticdrivetrain. This acoustic drivetrain includes transducer assembly (12),a rigid acoustic waveguide (180), and a flexible acoustic waveguide(166). Transducer assembly (12) includes a set of piezoelectric discs(not shown) located proximal to a horn (not shown) of rigid acousticwaveguide (180). The piezoelectric discs are operable to convertelectrical power into ultrasonic vibrations, which are then transmittedalong rigid acoustic waveguide (180) and flexible waveguide (166) toblade (160) in accordance with known configurations and techniques. Byway of example only, this portion of the acoustic drivetrain may beconfigured in accordance with various teachings of various referencesthat are cited herein.

Rigid acoustic waveguide (180) distally terminates in a coupling (188),which can be seen in FIGS. 4-7. Coupling (188) is secured to coupling(168) by a double-threaded bolt (169). Coupling (168) is located at theproximal end of flexible acoustic waveguide (166). As best seen in FIGS.3 and 5-7, flexible acoustic waveguide (166) includes a distal flange(136), a proximal flange (138), and a narrowed section (164) locatedbetween flanges (138). In the present example, flanges (136, 138) arelocated at positions corresponding to nodes associated with resonantultrasonic vibrations communicated through flexible acoustic waveguide(166). Narrowed section (164) is configured to allow flexible acousticwaveguide (166) to flex without significantly affecting the ability offlexible acoustic waveguide (166) to transmit ultrasonic vibrations. Byway of example only, narrowed section (164) may be configured inaccordance with one or more teachings of U.S. patent application Ser.No. 13/538,588 and/or U.S. patent application Ser. No. 13/657,553, thedisclosures of which are incorporated by reference herein. It should beunderstood that either waveguide (166, 180) may be configured to amplifymechanical vibrations transmitted through waveguide (166, 180).Furthermore, either waveguide (166, 180) may include features operableto control the gain of the longitudinal vibrations along waveguide (166,180) and/or features to tune waveguide (166, 180) to the resonantfrequency of the system.

In the present example, the distal end of blade (160) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible acoustic waveguide(166), in order to tune the acoustic assembly to a preferred resonantfrequency f_(o) when the acoustic assembly is not loaded by tissue. Whentransducer assembly (12) is energized, the distal end of blade (160) isconfigured to move longitudinally in the range of, for example,approximately 10 to 500 microns peak-to-peak, and in some instances inthe range of about 20 to about 200 microns at a predetermined vibratoryfrequency f_(o) of, for example, 55.5 kHz. When transducer assembly (12)of the present example is activated, these mechanical oscillations aretransmitted through waveguides (180, 166) to reach blade (160), therebyproviding oscillation of blade (160) at the resonant ultrasonicfrequency. Thus, when tissue is secured between blade (160) and clamppad (46), the ultrasonic oscillation of blade (160) may simultaneouslysever the tissue and denature the proteins in adjacent tissue cells,thereby providing a coagulative effect with relatively little thermalspread. In some versions, an electrical current may also be providedthrough blade (160) and clamp arm (44) to also cauterize the tissue.While some configurations for an acoustic transmission assembly andtransducer assembly (12) have been described, still other suitableconfigurations for an acoustic transmission assembly and transducerassembly (12) will be apparent to one or ordinary skill in the art inview of the teachings herein. Similarly, other suitable configurationsfor end effector (40) will be apparent to those of ordinary skill in theart in view of the teachings herein.

B. Exemplary Shaft Assembly and Articulation Section

FIGS. 2-7 show articulation section (130), which is located at thedistal end of shaft assembly (30), with end effector (40) being locateddistal to articulation section (130. Shaft assembly (30) of the presentexample extends distally from handle assembly (20). Shaft assembly (30)includes an outer sheath (32) that encloses drive features and theabove-described acoustic transmission features. As shown in FIG. 1, aknob (31) is secured to the proximal portion of outer sheath (32). Knob(31) is rotatable relative to body (22), such that shaft assembly (30)is rotatable about the longitudinal axis defined by sheath (32),relative to handle assembly (20). Such rotation may provide rotation ofend effector (40), articulation section (130), and shaft assembly (30)unitarily. Of course, rotatable features may simply be omitted ifdesired.

Articulation section (130) is operable to selectively position endeffector (40) at various lateral deflection angles relative to thelongitudinal axis defined by sheath (32). Articulation section (130) maytake a variety of forms. By way of example only, articulation section(130) may be configured in accordance with one or more teachings of U.S.Pub. No. 2012/0078247, the disclosure of which is incorporated byreference herein. As another merely illustrative example, articulationsection (130) may be configured in accordance with one or more teachingsof U.S. patent application Ser. No. 13/538,588 and/or U.S. patentapplication Ser. No. 13/657,553, the disclosures of which areincorporated by reference herein. Various other suitable forms thatarticulation section (130) may take will be apparent to those ofordinary skill in the art in view of the teachings herein.

As best seen in FIGS. 2-4 articulation section (130) of the presentexample comprises a first ribbed body portion (132) and a second ribbedbody portion (134), with a pair of articulation cables (140, 142)extending through channels defined at the interfaces between ribbed bodyportions (132, 134). Ribbed body portions (132, 134) are substantiallylongitudinally positioned between flanges (136, 138) of flexibleacoustic waveguide (166). The distal ends of articulation cables (140,142) are unitarily secured to distal flange (136). Articulation cables(140, 142) also pass through proximal flange (138), yet articulationcables (140, 142) are slidable relative to proximal flange (138). As onearticulation cable (140, 142) is pulled proximally, this will causearticulation section (130) to bend, thereby laterally deflecting endeffector (40) away from the longitudinal axis of shaft assembly (30) atan articulation angle as shown in FIGS. 6A-6B. In particular, endeffector (40) will be articulated toward the articulation cable (140,142) that is being pulled proximally. During such articulation, theother articulation cable (140, 142) will be pulled distally by flange(136). Ribbed body portions (132, 134) and narrowed section (164) areall sufficiently flexible to accommodate the above-describedarticulation of end effector (40). Furthermore, flexible acousticwaveguide (166) is configured to effectively communicate ultrasonicvibrations from rigid acoustic waveguide (180) to blade (160) even whenarticulation section (130) is in an articulated state as shown in FIG.6B.

II. Exemplary Articulation Drive Mechanisms

As noted above, articulation section (130) may be driven to articulateby driving one or both of articulation cables (140, 142) longitudinally.By way of example only, one articulation cable (140, 142) may beactively driven distally while the other articulation cable (140, 142)is passively permitted to retract proximally. As another merelyillustrative example, one articulation cable (140, 142) may be activelydriven proximally while the other articulation cable (140, 142) ispassively permitted to advance distally. As yet another merelyillustrative example, one articulation cable (140, 142) may be activelydriven distally while the other articulation cable (140, 142) isactively driven proximally. The following examples include variousfeatures that may be used to drive one or both of articulation cables(140, 142) longitudinally, to thereby articulate articulation section(130). It should be understood that the features described below may bereadily incorporated into instrument (10) in numerous ways. Othersuitable features that may be used to drive one or both of articulationcables (140, 142) longitudinally will be apparent to those of ordinaryskill in the art in view of the teachings herein.

A. Exemplary Articulation Drive Mechanism with Rack and Dual Pinions

FIGS. 8-10B show an exemplary mechanism (200) for driving longitudinalmovement of articulation cables (140, 142). Mechanism (200) may bepartially or completely positioned within handle assembly (20).Mechanism (200) of this example comprises a pair of gears (210, 220)rotatably disposed on opposite ends of an axle (202). In some versions,axle (202) is rotatably supported by body (22). In some other versions,axle (202) is rotatably supported by rigid acoustic waveguide (180). Forinstance, axle (202) may be located at a position along the length ofwaveguide (180) corresponding to a node associated with resonantultrasonic vibrations communicated through waveguide (180). Regardlessof where or how axle (202) is supported, gears (210, 220) are operableto rotate about an axis defined by axle (202).

Each gear (210, 220) includes a plurality of teeth (212, 222) disposedabout an exterior circumference of each gear (210, 220). As best seen inFIG. 8, a proximal end of articulation cable (140) is coupled to anexterior surface of gear (210) and a proximal end of articulation cable(142) is coupled to an exterior surface of gear (220). As best seen inFIGS. 10A-10B, the fixation points of the proximal ends of cables (140,142) are radially offset from the longitudinal axis of axle (202). Asalso seen in FIGS. 10A-10B, the fixation points of the proximal ends ofcables (140, 142) are angularly offset relative to each other. In thepresent example, the angular offset is approximately 180°, though itshould be understood that any other suitable angular offset may be used.It should also be understood that the proximal ends of cables (140, 142)may be pivotally coupled with respective gears (210, 220). For instance,such a pivotal coupling may permit articulation cables (140, 142) tomaintain a substantially parallel relationship with each other in theregion near gears (210, 220) as gears (210, 220) are rotated, withoutcreating a tendency for cables (140, 142) to bind or wind uponthemselves.

Mechanism (200) of the present example further comprises a rack member(230). Rack member (230) comprises a plurality of teeth (232). Teeth(232) of rack member (230) are configured to concurrently engage teeth(212, 222) of gears (210, 220). In some versions, a single set of teeth(232) simultaneously engages both sets of teeth (212, 222). In someother versions, rack member (230) has two separate sets of teeth—one setto engage teeth (212) and another set to engage teeth (222). Rack member(230) is coupled with a trigger (234) via a coupling (236), such thattrigger (234) is operable to move rack member (230) longitudinally. Insome instances, trigger (234) protrudes from or is otherwise exposedrelative to body (22). As will be discussed in more detail below,longitudinal movement of rack member (230) causes concurrent rotation ofgears (210, 220) to thereby cause opposing longitudinal movement ofarticulation cables (140, 142), thus deflecting articulation section(130).

In some versions, coupling (236) comprises a slip washer. By way ofexample only, rack member (230) may orbitally rotate about the outerperimeter of coupling (236). In some such versions, axle (202) issecured to waveguide (180), such that axle (202), gears (210, 220), rackmember (230), waveguide (180), and the remainder of shaft assembly (30)and end effector (40) all rotate about the longitudinal axis ofwaveguide (180) while trigger (234) remains rotationally stationary. Asanother merely illustrative example, coupling (236) may be rotatablycoupled with trigger (234), such that coupling (236) rotates with axle(202), gears (210, 220), rack member (230), waveguide (180), and theremainder of shaft assembly (30) and end effector (40) about thelongitudinal axis of waveguide (180) while trigger (234) remainsrotationally stationary. In versions where axle (202) is supported bywaveguide (180), it should be understood that coupling (236) may includean opening configured to accommodate waveguide (180); and that trigger(234) may also be configured to avoid direct contact with waveguide(180).

FIG. 10A shows mechanism (200) in a first position. In this firstposition, rack member (230) is in a first longitudinal position andgears (210, 220) are in a first rotational position. When mechanism(200) is in the first position, articulation section (130) is in astraight configuration (FIG. 6A). A user may actuate trigger (234) tothereby drive rack member (230) into a second longitudinal position asshown in FIG. 10B. Longitudinal movement of rack member (230) will causeconcurrent rotation of gears (210, 220). Because articulation cables(140, 142) are coupled to angularly opposed regions of the exteriorsurface of gears (210, 220), concurrent rotation of gears (210, 220)drives articulation cables (140, 142) in opposite longitudinaldirections. For instance, as shown in FIG. 10B, clockwise rotation ofgears (210, 220) will cause proximal longitudinal movement ofarticulation cable (142) and distal longitudinal movement ofarticulation cable (140). Alternatively, counter-clockwise rotation ofgears (210, 220) will cause distal longitudinal movement of articulationcable (142) and proximal longitudinal movement of articulation cable(140).

It should be understood that articulation cables (140, 142) may bepositioned at different radial distances from axle (202) to therebyincrease/decrease the amount of longitudinal movement that rotation ofgears (210, 220) will cause to each cable (140, 142). Furthermore,although articulation cables (140, 142) are positioned a similar radialdistance from axle (202) in the present example, articulation cables(140, 142) may be positioned at different radial distances to therebyincrease/decrease the amount of longitudinal movement that rotation ofgears (210, 220) will cause to each cable (140, 142) independently.

B. Exemplary Articulation Drive Mechanism with Clutching Driver andOpposing Lead Screws

FIGS. 11-12C show an exemplary alternative mechanism (300) for drivinglongitudinal movement of articulation cables (140, 142). Mechanism (300)may be partially or completely positioned within handle assembly (20).Mechanism (300) of this example comprises a rotation knob (310), a shaftassembly rotation driver (320), and an articulation drive nut (330). Inthe present example, rotation knob (310) is a variation of knob (31)described above. Rotation knob (310) includes an integral, proximallyextending sleeve (312). Sleeve (312) presents an array of longitudinallyoriented, inwardly extending splines (348). Rotation knob (310) isconfigured to slide longitudinally to selectively engage splines (348)with either rotation driver (320) or articulation drive nut (330). Inparticular, and as will be described in greater detail below, rotationknob (310) is engaged with rotation driver (320) when rotation knob(310) is in a distal position; and rotation knob (310) is engaged witharticulation drive nut (330) when rotation knob (310) is in a proximalposition. In the distal position, rotation knob (310) is operable torotate rotation driver (320) to thereby rotate shaft assembly (30) andend effector (40). In the proximal position, rotation knob (310) isoperable to rotate articulation drive nut (330) to thereby articulatearticulation section (130). It should be understood that a detentfeature, over-center feature, and/or some other kind of feature may beoperable to selectively maintain rotation knob (310) in either thedistal position or the proximal position.

Rotation driver (320) is operable to rotate shaft assembly (30) and endeffector (40), relative to handle assembly (20), about the longitudinalaxis defined by shaft assembly (30). In particular, rotation driver(320) is secured to waveguide (180) by a pin (322), which is located ata position along the length of waveguide (180) corresponding to a nodeassociated with resonant ultrasonic vibrations communicated throughwaveguide (180). Waveguide (180) thus rotates concomitantly withrotation driver (320). The remainder of shaft assembly (30) will alsorotate with rotation driver (320). The exterior of the proximal region(324) of rotation driver (322) includes a set of longitudinally orientedsplines (not shown) extending radially outwardly from rotation driver(322). These splines mesh with complementary inwardly extending splines(348) in sleeve (312) of rotation knob (310) when rotation knob (310) isin a distal position as shown in FIG. 12A. This engagement betweensplines (348) of sleeve (312) and the splines of rotation driver (320)provides rotation of rotation driver (322) (and its associatedcomponents) in response to rotation of rotation knob (310). Whenrotation knob (310) is in a proximal position as shown in FIGS. 12B-12C,splines (348) of sleeve (312) are disengaged from the splines ofrotation driver (320), such that rotation of rotation knob (310) willnot rotate rotation driver (322) or its associated components. It shouldbe understood that one or more features may selectively lock therotational position of rotation driver (322) and/or its associatedcomponents when rotation knob (310) is shifted to the proximal positionshown in FIG. 12B-12C.

As best seen in FIG. 11, the exterior of a distal portion ofarticulation drive nut (330) includes a set of longitudinally orientedsplines (331) extending radially outwardly from drive nut (330). Thesesplines (331) are configured to mesh with splines (348) of sleeve (312)of rotation knob (310) when rotation knob (310) is in a proximalposition as shown in FIGS. 12B-12C. This engagement between splines(348) of sleeve (312) and splines (331) of articulation drive nut (330)provides rotation of articulation drive nut (330) in response torotation of rotation knob (310). When rotation knob (310) is in a distalposition as shown in FIG. 12A splines (348) of sleeve (312) aredisengaged from splines (331) of articulation drive nut (330), such thatrotation of rotation knob (310) will not articulation drive nut (330).As best seen in FIGS. 12A-12C, the interior of articulation drive nut(330) defines a first internal thread region (332) and a second internalthread region (334). In the present example, first internal threadregion (332) and second internal thread region (334) comprise opposingthreading (i.e., oriented at opposing pitches). For instance, firstinternal thread region (332) may have a right-handed thread pitch whilesecond internal thread region (334) has a left-handed thread pitch, orvice-versa.

A first lead screw (336) is disposed within first internal thread region(332) while second lead screw (338) is disposed in second internalthread region (334). First lead screw (336) presents a first externalthread (340) that complements the threading of first internal threadregion (332) of articulation drive nut (330). Second lead screw (338)presents a second external thread (342) that complements the threadingof second internal thread region (334) of articulation drive nut (330).Pins (344, 346) are slidably disposed within first lead screw (336) andsecond lead screw (338). Pins (344, 346) are mounted within handleassembly (20) such that pins (344, 346) are unable to rotate. Thus, asarticulation drive nut (330) rotates, pins (344, 346) prevent first leadscrew (336) and second lead screw (338) from rotating but allow firstlead screw (336) and second lead screw (338) to translatelongitudinally. As noted above, first internal thread region (332) andsecond internal thread region (334) have opposing thread pitches, suchthat rotation of articulation drive nut (330) in a single directioncauses opposing translation of lead screws (336, 338) withinarticulation drive nut (330). Thus rotation of articulation drive nut(330) will cause translation of first lead screw (336) in a firstlongitudinal direction within first internal thread region (332) ofarticulation drive nut (330) and simultaneous translation of second leadscrew (338) in a second longitudinal direction within second internalthread region (334) of articulation drive nut (330), as shown in FIG.12C.

As shown in FIGS. 12A-12C, articulation cable (140) is coupled withfirst lead screw (336) such that articulation cable (140) translatesunitarily with first lead screw (336). Articulation cable (142) iscoupled with second lead screw (338) such that articulation cable (142)translates unitarily with second lead screw (338). It should thereforebe understood that articulation cables (140, 142) will translate in anopposing fashion in response to rotation of articulation drive nut(330), thus causing articulation of articulation section (130). Rotatingdrive nut (330) in one rotational direction will cause articulation ofarticulation section (130) in a first direction of articulation; whilerotating drive nut (330) in another rotational direction will causearticulation of articulation section (130) in an opposite direction ofarticulation. It should be understood from the foregoing that thearticulation driving features of mechanism (300) may be configured andoperable in accordance with at least some of the teachings of U.S. Pub.No. 2013/0023868, entitled “Surgical Instrument with Contained DualHelix Actuator Assembly,” published Jan. 24, 2013, the disclosure ofwhich is incorporated by reference herein.

C. Exemplary Articulation Drive Mechanism with Offset Motor and OpposingLead Screws

FIGS. 13A-13B show another exemplary alternative mechanism (400) fordriving longitudinal movement of articulation cables (140, 142).Mechanism (400) may be partially or completely positioned within handleassembly (20). Mechanism (400) of this example comprises a motor (410),a drive shaft (420), and a pair of drive nuts (428, 430). Motor (410) isoriented along a motor axis (MA) that is parallel to yet laterallyoffset from the longitudinal axis of waveguide (180). Motor (410) ismechanically coupled with a gear (412) such that motor (410) is operableto rotate gear (412). Gear (412) comprises a plurality of teeth (414)disposed about an exterior circumference of gear (412). Drive shaft(420) is coaxially disposed about waveguide (180). One or more setoffmembers (430) are coaxially interposed between waveguide (180) and driveshaft (420). Setoff member (430) is located at a position along thelength of waveguide (180) corresponding to a node associated withresonant ultrasonic vibrations communicated through waveguide (180).Setoff member (430) is configured to support drive shaft (430) whileallowing drive shaft to rotate relative to waveguide (180). Varioussuitable forms that setoff member (430) may take will be apparent tothose of ordinary skill in the art in view of the teachings herein.

A central region of drive shaft (420) comprises a plurality of teeth(422) disposed about an exterior circumference of drive shaft (420).Teeth (414) of gear (412) engage teeth (422) of drive shaft (420) suchthat rotation of gear (412) causes rotation of drive shaft (420) aboutthe longitudinal axis of waveguide (180). A distal region of drive shaft(420) comprises a first external threading (424) while a proximal regionof drive shaft (420) comprises a second external threading (426). Firstand second external threading (424, 426) have opposing pitch (i.e.,opposing thread orientation). For instance, first external threading(424) may have a right-handed thread pitch while second externalthreading (426) has a left-handed thread pitch, or vice-versa.

A first drive nut (428) is disposed over first external threading (424).First drive nut (428) has a first internal threading that complementsfirst external threading (424). A second drive nut (430) is disposedover second external threading (426). Second drive nut (424) has asecond internal threading that complements second external threading(426). Drive nuts (428, 430) are secured within handle assembly (20)such that drive nuts (428, 430) may translate within handle assembly(20) but not rotate within handle assembly (20). Thus, when drive shaft(420) rotates within handle assembly (20), drive nuts (428, 430) willtranslate in opposing longitudinal direction due to the configurationsof threading (424, 426). For instance, in the transition between FIG.13A and FIG. 13B, drive shaft (420) has rotated such that first drivenut (428) has translated distally while second drive nut (430) hassimultaneously translated proximally. Various suitable ways in whichdrive nuts (428, 430) may be secured within handle assembly (20) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As also shown in FIGS. 13A-13B, articulation cable (140) is coupled withfirst drive nut (428) such that articulation cable (140) translatesunitarily with first drive nut (428). Articulation cable (142) iscoupled with second drive nut (430) such that articulation cable (142)translates unitarily with second drive nut (430). It should therefore beunderstood that articulation cables (140, 142) will translate in anopposing fashion in response to rotation of drive shaft (420), thuscausing articulation of articulation section (130). It should beunderstood that rotating drive shaft (420) in one rotational directionwill cause articulation of articulation section (130) in a firstdirection of articulation; while rotating drive shaft (420) in anotherrotational direction will cause articulation of articulation section(130) in an opposite direction of articulation

D. Exemplary Articulation Drive Mechanism with Pinion and Opposing Racks

FIGS. 14-15B show another exemplary alternative mechanism (500) fordriving longitudinal movement of articulation cables (140, 142).Mechanism (500) may be partially or completely positioned within handleassembly (20). Mechanism (500) of this example comprises a pair of rackmembers (510, 520) and a pinion gear (530). Rack members (510, 520) areslidably disposed in body (22). Rack members (510, 520) each comprises aplurality of teeth (512, 522) disposed along an interior surface of rackmembers (510, 520). Pinion gear (530) comprises a plurality of teeth(532) disposed about an exterior circumference of gear (430). Rackmember (510) is oriented such that teeth (512) of rack member (510)engage teeth (532) of pinion gear (530), such that rotation of piniongear (530) causes longitudinal translation of rack member (510).Similarly, rack member (520) is oriented such that teeth (522) of rackmember (520) engage teeth (532) of pinion gear (530), such that rotationof pinion gear (530) causes longitudinal translation of rack member(520). In some versions, pinion gear (530) is rotated by a motor. Insome other versions, pinion gear (530) is driven manually (e.g., by adial, lever, knob, etc.). Various suitable ways in which pinion gear(530) may be driven will be apparent to those of ordinary skill in theart in view of the teachings herein.

As best seen in FIG. 14, teeth (512) of rack member (510) and teeth(522) of rack member (520) engage teeth (532) of pinion gear (530) onopposite sides of pinion gear (530). Thus, it should be understood thatrotation of pinion gear (530) in a single direction will causelongitudinal translation of rack members (510, 520) in oppositedirections simultaneously. For instance, clockwise rotation of piniongear (530) will cause proximal longitudinal translation of rack member(510) and simultaneous distal longitudinal translation of rack member(520) as shown in FIG. 15B. Alternatively, counter-clockwise rotation ofpinion gear (530) will cause distal longitudinal translation of rackmember (510) and simultaneous proximal longitudinal translation of rackmember (520). As shown in FIGS. 15A-15B, articulation cable (140) iscoupled with rack member (510). Articulation cable (142) is coupled withsecond rack member (520). It should therefore be understood thatarticulation cables (140, 142) will translate distally and/orproximally, in opposing fashion, in response to rotation of pinion gear(530), thereby causing articulation of articulation section (130).

In some versions, articulation cable (140) is coupled with rack member(510) via a washer, bushing, or other rotatable feature that isrotatably disposed about waveguide (180). Similarly, articulation cable(142) may be coupled with rack member (520) via a washer, bushing, orother rotatable feature that is rotatably disposed about waveguide(180). In some such versions, rack members (510, 520) do not rotatewithin body (22), yet cables (140, 142) may orbitally rotate about thelongitudinal axis of waveguide (180) (e.g., as shaft assembly (30) andend effector (40) are also rotated), while still maintaining aconnection with rack members (510, 520). Other suitable ways in whichrotation of shaft assembly (30) and end effector (40) may beaccommodated will be apparent to those of ordinary skill in the art inview of the teachings herein.

E. Exemplary Articulation Drive Mechanism with Lever and Pawl

FIGS. 16A-16B show another exemplary alternative mechanism (600) fordriving longitudinal movement of articulation cables (140, 142).Mechanism (600) may be at least partially positioned within handleassembly (20). Mechanism (600) of this example comprises a rotatingmember (610), a lever (620), and a locking member (630). Rotating member(610) and lever (620) are rotatably disposed about an axle (602). Lever(620) is fixedly coupled to rotating member (610) such that rotation oflever (620) about axle (602) causes rotation of rotating member (610)about axle (602). In some versions, at least a portion of lever (620) isexposed relative to body (22) (e.g., near pistol grip (24)), enabling anoperator to contact and drive lever (620) with the operator's finger orthumb. As shown in FIG. 16A, a proximal end of articulation cable (140)is pivotally coupled to an upper portion of rotating member (610); and aproximal end of articulation cable (142) is pivotally coupled to a lowerportion of rotating member (610). The pivotal nature of these couplingspermits articulation cables (140, 142) to maintain a substantiallyparallel relationship with each other as rotating member (610) isrotated, without articulation cables (140, 142) binding or wrapping,etc.

Locking member (630) is pivotable about a pin (604). An exteriorcircumference of rotating member (610) presents a recess (612). As shownin FIG. 16A, locking member (630) presents a tooth (632) configured toengage recess (612) to thereby prevent rotating member (610) fromrotating about axle (602). As shown in FIG. 16B, to disengage lockingmember (630) from recess (612), a user may apply pressure to a thumbpaddle (634) of locking member (630) to thereby rotate locking member(630) about pin (604), thus removing tooth (632) from recess (612). Insome versions, at least a portion of thumb paddle (634) may be exposedrelative to body (22) to enable direct manipulation by a user's thumb orfinger. Locking member (630) may be resiliently biased toward thelocking position shown in FIG. 16A. For instance, a torsion spring (notshown) may rotate locking member (630) toward the locking position. Inthe present example, recess (612) is located at a position correspondingto articulation section (130) being in a non-articulated state. Itshould be understood that recess (612) may be located elsewhere and/orthat other recesses (612) may be included. For instance, a plurality ofrecesses (612) may be used to provide selective locking of articulationsection (130) in various states of articulation. Other suitable ways inwhich articulation section (130) may be selectively locked will beapparent to those of ordinary skill in the art in view of the teachingsherein.

FIG. 16A shows mechanism (600) in a first position. In this firstposition, rotating member (610) and lever (620) are in a firstrotational position. It should be understood that with mechanism (600)in the first position, articulation section (130) is in a straightconfiguration (FIG. 6A). The operator may depress thumb paddle (634) tounlock rotating member (610); and actuate lever (620) to thereby driverotating member (610) into a second rotational position as shown in FIG.16B. Because articulation cables (140, 142) are coupled to oppositeportions of rotating member (610), rotation of rotating member (610)drives articulation cables (140, 142) in opposite longitudinaldirections. For instance, as shown in FIG. 16B, clockwise rotation ofrotating member (610) will cause proximal longitudinal movement ofarticulation cable (140) and distal longitudinal movement ofarticulation cable (142). This drives articulation section (130) to anarticulated state, as shown in FIG. 6B.

It should be understood that articulation cables (140, 142) may bepositioned at different radial distances from axle (602) to therebyincrease/decrease the amount of longitudinal movement that rotation ofrotating member (610) will cause to each cable (140, 142). Furthermore,although in the present example articulation cables (140, 142) arepositioned a similar radial distance from axle (602), articulationcables (140, 142) may be positioned at different radial distances tothereby increase/decrease the amount of longitudinal movement thatrotation of rotating member (610) will cause to each cable (140, 142)independently. In some alternative versions, cables (140, 142) areconsolidated into a single cable that wraps around a proximal portion ofthe outer perimeter of rotating member (610) similar to a pulley wheelarrangement. As yet another merely illustrative variation, cables (140,142) may be coupled with the free ends of a flexible drive member thatwraps about a proximal portion of the outer perimeter of rotating member(610). Such a flexible drive member may include outwardly extendingteeth that selectively engage tooth (632) in a ratcheting fashion, suchthat the flexible drive member and locking member (630) cooperate toselectively maintain the longitudinal positioning of cables (140, 142).Other suitable configurations and arrangements will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

III. Exemplary Articulation with Single Translating Driver

The examples described above include a pair of translatingdrivers—articulation cables (140, 142)—to drive articulation ofarticulation section (130). It should be understood that it is alsopossible to use just a single translating driver to drive articulationof articulation section (130). For instance, a single translating drivermay be retracted proximally from a home position to articulatearticulation section (130) in a single direction; then be returneddistally to the home position to return articulation section (130) to asubstantially straight configuration. FIGS. 17A-17B show an exemplaryconfiguration for driving articulation of articulation section (130)using a single translating driver. In particular, FIGS. 17A-17B show aversion of instrument (10) having a single articulation drive band(740). The proximal end of articulation drive band (740) is secured to acoupler (710). The distal end of articulation drive band (740) issecured to a distal collar (748) of articulation section (130). Coupler(710) is coaxially and slidably disposed about waveguide (180). Coupler(710) comprises a distal flange (712) and a proximal flange (714), whichtogether define a channel (716) therebetween. Coupler (710) isconfigured to rotate with band (740), shaft assembly (30), and endeffector (740) in response to rotation of knob (31).

Body (20) includes a link (730) in this example. One end of link (730)is pivotally coupled with trigger (28), while the other end of link(730) is pivotally coupled with a translating driver (720). Link (730)is configured to pivot and translate within body (20), while driver(720) is configured to only translate (without rotating) in body (20).The distal end of driver (720) includes a yoke (722), which ispositioned in channel (716) of coupler (710). The engagement betweenyoke (722) and coupler (710) provides longitudinal translation ofcoupler (710) (and, hence, band (740)) in response to longitudinaltranslation of driver (720). However, the engagement between yoke (722)and coupler (710) also permits coupler (710) to rotate within yoke(722). It should be understood that link (730) converts pivotal motionof trigger (28) toward and away from grip (24) into longitudinal motionof driver (720), coupler (710), and band (740). Such motion is depictedin the series of FIGS. 17A-17B, in which driver (720), coupler (710),and band (740) translate proximally in response to trigger (28) beingpivoted toward grip (24). As can also be seen in FIGS. 17A-17B, theproximal movement of band (740) causes articulation section (130) toarticulate away from the longitudinal axis of shaft assembly (30),thereby positioning end effector (740) at an articulated position. Whentrigger (28) is driven away from grip (24) to the position shown in FIG.17A, articulation section (130) and end effector (740) also return to aposition where articulation section (130) and end effector (740) arealigned with the longitudinal axis of shaft assembly (30). In someinstances, trigger (28) and/or other features are resiliently biased toassume the configuration shown in FIG. 17A, such that the operator needonly relax their grip on trigger (28) to return from the configurationshown in FIG. 17B to the configuration shown in FIG. 17A.

End effector (740) of the present example comprises a hook-shapedultrasonic blade (742). Blade (742) is angularly oriented such thatarticulation section (130) bends along an angular path that issubstantially parallel the gap (744) defined by the hook-shapedconfiguration. Of course, any other suitable kind of end effector may beused; and the geometry of the end effector may have any other suitablerelationship with the operation of articulation section (130). Whilearticulation section (130) deflects end effector (740) away from thelongitudinal axis of shaft assembly (30) in only one direction in thepresent example, it should be understood that the rotatability of shaftassembly (30) and end effector (740) may nevertheless provide selectivepositioning of blade (742) at various orientations. For instance, anoperator may manipulate knob (31) to first achieve a desired angularorientation; then manipulate trigger (28) to articulate blade (742) at adesired angle of articulation. Alternatively, the operator may firstmanipulate trigger (28) to articulate blade (742) at a desired angle ofarticulation; then manipulate knob (31) to achieve a desired angularorientation. Other suitable methods of operation will be apparent tothose of ordinary skill in the art in view of the teachings herein. Itshould also be understood that another articulation band may be providedfor articulation along another path. Such an additional articulationband may have a corresponding coupler, yoke, and trigger, etc.

IV. Exemplary Alternative Articulation Section Configurations

The foregoing examples of articulation drive mechanisms have all beendiscussed in the context of articulation section (130). It should beunderstood that articulation section (130) is just one merelyillustrative example, and that the various articulation drive mechanismteachings above may be readily applied to various other kinds ofarticulation sections. Several examples of alternative articulationsections will be described in greater detail below. Still furtherexamples of alternative articulation sections will be apparent to thoseof ordinary skill in the art in view of the teachings herein. Similarly,various suitable ways in which the articulation drive mechanismsdescribed herein may be incorporated with the various alternativearticulation sections described herein will be apparent to those ofordinary skill in the art.

A. Exemplary Articulation Section with Curved Bias

FIGS. 18A-18B show an exemplary alternative articulation section (800)that may be interposed between shaft assembly (30) and end effector (40)in place of articulation section (130), to selectively position endeffector (40) at various lateral deflection angles relative to thelongitudinal axis defined by shaft assembly (30). Articulation section(800) of the present example comprises a ribbed body (810), with asingle articulation band (840) extending through a channel definedwithin ribbed body (810). Ribbed body (810) comprises a first pluralityof ribs (812) and a second plurality of ribs (814) disposed on oppositesides of ribbed body (810). Ribs (812) define a plurality of gaps (820).Ribs (814) also define a plurality of gaps (830). Gaps (820, 830) areconfigured to promote bending of ribbed body (810).

As shown in FIG. 18A, ribbed body (810) is configured to have an initialbent configuration thus defining a first side of ribbed body (810) whichfollows a circumference having a first radius and a second side ofribbed body (810) which follows a circumference having a second(smaller) radius. Ribbed body (810) is preformed to resiliently assumethe bent configuration shown in FIG. 18A. Each gap (820) includes a pairof boss surfaces (822) that engage each other when ribbed body (810) isin the bent configuration shown in FIG. 18A. This engagement betweenboss surfaces (822) provides a hard stop that restricts the bend angleof articulation section (800).

Ribs (812) are disposed on the side of ribbed body (810) that follows acircumference having the second, smaller radius when articulationsection (800) is in the bent configuration. Ribs (814) are disposed onthe side of ribbed body (810) that follows a circumference having thefirst, larger radius when articulation section (800) is in the bentconfiguration. Ribbed body (810) is longitudinally positioned betweenflanges (136, 138) of flexible acoustic waveguide (166). The distal endof articulation cable (140) is unitarily secured to distal flange (136).Articulation cable (140) also passes through ribs (814) proximal flange(138), yet articulation cable (140) is slidable relative to ribs (814)and proximal flange (138). In addition to (or as an alternative to)ribbed body (810) being preformed to resiliently assume the bent stateshown in FIG. 18A, flexible waveguide (166) may be preformed toresiliently assume the bent state shown in FIG. 18A.

As articulation band (840) is pulled proximally, this will causearticulation section (800) to bend away from the state shown in FIG.18A, thereby deflecting end effector (40) toward the longitudinal axisof shaft assembly (30) as shown in FIG. 18B. In particular, end effector(40) will be articulated toward articulation cable (140) untilarticulation section (800) reaches a substantially straightconfiguration. To re-bend articulation section (800), articulation band(840) may simply be released, such that the resilient bias of ribbedbody (810) and/or the resilient bias of flexible waveguide (166)resiliently returns articulation section (800) to the bent state shownin FIG. 18A. In addition or in the alternative, articulation band (840)may be driven distally to assist in the re-bending of articulationsection (800) to the position shown in FIG. 18A. Ribbed body (810) andnarrowed section (164) are all sufficiently flexible to accommodate theabove-described bending and straightening of articulation section (800).To the extent that an operator wishes to selectively lock articulationsection (800) at some partially bent state (e.g., between the positionshown in FIG. 18A and the position shown in FIG. 18B), one or morelocking features may be manipulated to selectively lock articulationsection (800) at such a partially bent state. Various suitable examplesof locking features that may be used for this purpose will be apparentto those of ordinary skill in the art in view of the teachings herein.

B. Exemplary Articulation Section with Articulation Bands

FIGS. 19-20B show another exemplary alternative articulation section(900) that may be interposed between shaft assembly (30) and endeffector (40) in place of articulation section (130), to selectivelyposition end effector (40) at various lateral deflection angles relativeto the longitudinal axis defined by shaft assembly (30). Articulationsection (900) of this example comprises a first ribbed body portion(932) and a second ribbed body portion (934), with pair of articulationbands (910, 912) extending through channels defined at the interfacesbetween ribbed body portions (932, 934). In some versions, waveguide(166) includes flat surfaces on the entire length along whicharticulation bands (910, 912) extend. In particular, such flat surfacesmay be located on laterally opposing sides of waveguide (166). Such flatsurfaces may provide accommodation for articulation bands (910, 912),such that the inclusion of articulation bands (910, 912) will notincrease the overall outer diameter presented by a combination ofarticulation bands (910, 912) and waveguide (166). In other words, theinner diameter and outer diameter of outer sheath (32) need not be anylarger than such diameters otherwise would be in a non-articulatingversion of instrument (10). By way of example only, flats may beprovided along the length of waveguide (166) in accordance with at leastsome of the teachings of U.S. patent application Ser. No. 13/868,336,entitled “Ultrasonic Device for Cutting and Coagulating,” filed Apr. 23,2013, the disclosure of which is incorporated by reference herein.Alternatively, such flat surfaces may take any other suitable form. Asanother alternative, such flat surfaces may simply be omitted. To theextent that the present application refers to an articulation band (910,912) extending “along” a flat lateral region of waveguide (166) itshould be understood that this does not mean that the articulation band(910, 912) would need to come into contact with waveguide (166). Itsimply means that the articulation band (910, 912) would simply residein a void left by the flat lateral region of waveguide (166) (i.e., avoid that would otherwise be occupied by the material forming waveguide(166) if that region of waveguide (166) had a circular cross-section).

Ribbed body portions (932, 934) are longitudinally positioned betweenouter sheath (32) and an outer tube (936). Ribbed body portions (932,934) are configured to flex to permit articulation of articulationsection (900) in response to opposing translation of articulation bands(910, 912) as shown in the series of FIGS. 20A-20B. Ribbed body portions(932, 934) thus permit sliding of articulation bands (910, 912) withinthe channels of ribbed body portions (932, 934). By way of example only,ribbed body portions (932, 934) and/or other features of articulationsection (900) may be configured in accordance with at least some of theteachings of U.S. Pub. No. 2012/0078247, entitled “Articulation JointFeatures for Articulating Surgical Device,” published Mar. 29, 2012, thedisclosure of which is incorporated by reference herein.

The distal ends of articulation bands (910, 912) are secured to a distalcollar (940). Distal collar (940) includes a distal flange (942) andprojections (944) that extend outwardly in an opposing fashion.Projections (944) are disposed in respective openings formed near thedistal ends of articulation bands (910, 912) thereby coupling distalcollar (940) with articulation bands (910, 912). Distal flange (942)abuts the distal edge of outer tube (936). In the example shown,projections (944) extend into an annular recess (938) formed withinouter tube (936), thereby providing a snap-fit coupling between distalcollar (940) and outer tube (936). In some other versions, annularrecess (938) is omitted. For instance, tension in articulation bands(910, 912) may suffice to substantially secure the position of distalcollar (940) relative to outer tube (936). Other suitable configurationsand relationships will be apparent to those of ordinary skill in the artin view of the teachings herein.

In the present example, articulation section (900) is configured suchthat a nodal portion (N) of waveguide (166) is positioned in outer tube(936), just proximal to where articulation bands (910, 912) are coupledwith collar (940). Nodal portion (N) corresponds with a distal nodeassociated with resonant ultrasonic vibrations communicated throughwaveguide (166). When articulation bands (910, 912) are translatedlongitudinally in an opposing fashion as shown in FIG. 20B, a moment iscreated and applied to nodal portion (N) through outer tube (936). Thiscauses articulation section (900) and narrowed section (164) ofwaveguide (166) to articulate, without transferring axial forces inarticulation bands (910, 912) to waveguide (166). In particular,articulation section (900) of the present example maintains a gap (945)between the proximal end of distal collar (940) and nodal portion (N) ofwaveguide (166), such that collar (940) does not bear proximally againsta distally facing surface of nodal portion (N), even when articulationsection (900) is in a bent state as shown in FIG. 20B. Thus, nodalportion (N) only receives laterally directed bearing forces (by outertube (936) and/or bands (910, 912)) when being driven to an articulatedposition as shown in FIG. 20B.

It should be understood that one articulation band (910, 912) may beactively driven distally while the other articulation band (910, 912) ispassively permitted to retract proximally. As another merelyillustrative example, one articulation band (910, 912) may be activelydriven proximally while the other articulation band (910, 912) ispassively permitted to advance distally. As yet another merelyillustrative example, one articulation band (910, 912) may be activelydriven distally while the other articulation band (910, 912) is activelydriven proximally. Various suitable ways in which articulation bands(910, 912) may be driven will be apparent to those of ordinary skill inthe art in view of the teachings herein.

In the discussion of the examples shown in FIGS. 18A-18B, it was notedhow boss surfaces (822) of ribbed body (810) engage each other whenribbed body (810) is bent to the configuration shown in FIG. 18A, suchthat boss surfaces (822) provide a hard stop that restricts the bendangle of articulation section (800). The same principle may apply toarticulation section (900) shown in FIGS. 19-20B. In particular, ribbedbody portions (932, 934) of the present example include opposingsurfaces (935) that may act as boss surfaces that engage each other onone side of articulation section (900) when articulation section (900)reaches a fully articulated state. Surfaces (935) may thus restrict thebend angle of articulation section (900) (e.g., to prevent narrowedsection (164) of waveguide (166) from overbending, etc.). Other suitableways in which the bend angle of articulation section (900) may berestricted will be apparent to those of ordinary skill in the art inview of the teachings herein.

C. Exemplary Articulation Section with Coaxial Segmented Regions

FIGS. 21-27 show another exemplary alternative articulation section(1000) that may be interposed between shaft assembly (30) and endeffector (40) in place of articulation section (130), to selectivelyposition end effector (40) at various lateral deflection angles relativeto the longitudinal axis defined by shaft assembly (30). Articulationsection (1000) of this example is formed by a segmented region (1012) ofan outer tube (1010) and a segmented region (1022) of an inner tube(1020). Tubes (1010, 1020) are coaxially aligned with each other. Outertube (1010) is rotatable and relative to inner tube (1020). Inner tube(1020) is translatable relative to outer tube (1010). As will bedescribed in greater detail below, such relative rotation of outer tube(1010) and translation of inner tube (1020) may be performed even whilearticulation section (1000) is in an articulated state.

Segmented region (1012) of outer tube (1010) comprises a plurality ofsegments (1012A, 1012B). Segments (1012A, 1012B) are joined to eachother and to the remainder of outer tube (1010) by coupling features(1013), which are best seen in FIG. 25. Coupling features (1013) are inthe form of rounded tabs that fit in complementary recesses in thisexample, though it should be understood that other configurations may beused. Each segment (1012A, 1012B) has a respective pair of couplingfeatures (1013), which provide hinged couplings between segments (1012A,1012B) and the rest of outer tube (1010). The coupling features (1013)in each pair are angularly offset from each other by 180°. Segments(1012A, 1012B) are also separated from each other and from the remainderof outer tube (1010) by gaps (1015). Each segment (1012A, 1012B) alsoincludes a pair of proximally oriented projections (1017) traversingrespective gaps (1015), as best seen in FIG. 21. The projections (1017)in each pair are angularly offset from each other by 180°. In eachsegment (1012A, 1012B), the coupling features (1013) are angularlyoffset from the projections (1017) by 90°, such that coupling features(1013) and projections (1017) are alternatingly and evenly positionedalong the proximally facing perimeter of each segment (1012A, 1012B).

Coupling features (1013), gaps (1015), and projections (1017) areconfigured to allow segmented region (1012) to flex. However,projections (1017) prevent segments (1012A, 1012B) from rotatingrelative to each other and relative to the remainder of outer tube(1010). In some versions, coupling features (1013), gaps (1015), andprojections (1017) are formed by a laser cutting process, though itshould be understood that any other suitable processes may be used.

Similarly, segmented region (1022) of inner tube (1020) comprises aplurality of segments (1022A, 1022B). Segments (1022A, 1022B, 1022C,1022D, 1022E) are joined to each other and to the remainder of innertube (1020) by coupling features (1023), which are best seen in FIG. 26.Each segment (1022A, 1022B, 1022C, 1022D, 1022E) has a respective pairof coupling features (1023), which provide hinged couplings betweensegments (1022A, 1022B, 1022C, 1022D, 1022E) and the rest of inner tube(1020). The coupling features (1023) in each pair are angularly offsetfrom each other by 180°. Segments (1022A, 1022B, 1022C, 1022D, 1022E)are also separated from each other and from the remainder of inner tube(1020) by gaps (1025). Each segment (1022A, 1022B, 1022C, 1022D, 1022E)also includes a pair of proximally oriented projections (1027)traversing respective gaps (1025), as best seen in FIG. 22. Theprojections (1027) in each pair are angularly offset from each other by180°. In each segment (1022A, 1022B, 1022C, 1022D, 1022E), the couplingfeatures (1023) are angularly offset from the projections (1027) by 90°,such that coupling features (1023) and projections (1027) arealternatingly and evenly positioned along the proximally facingperimeter of each segment (1022A, 1022B, 1022C, 1022D, 1022E).

Coupling features (1023), gaps (1025), and projections (1027) areconfigured to allow segmented region (1022) to flex. Projections (1017)are configured to prevent segments (1022A, 1022B, 1022C, 1022D, 1022E)from rotating relative to each other and relative to the remainder ofinner tube (1020). As noted above, inner tube (1020) is translatablerelative to outer tube (1010). Coupling features (1023), gaps (1025),and projections (1027) are configured to allow segmented region (1022)to translate longitudinally relative to segmented region (1012), evenwhen segmented regions (1012, 1022) are both in a bent configuration. Insome versions, coupling features (1023), gaps (1025), and projections(1027) are formed by a laser cutting process, though it should beunderstood that any other suitable processes may be used.

Waveguide (166) extends coaxially through inner tube (1020). As bestseen in FIGS. 23-24, a set of spacers (1002) are used to maintainseparation between waveguide (166) and inner tube (1020). Spacers (1002)are located at positions corresponding to nodes associated with resonantultrasonic vibrations communicated through flexible acoustic waveguide(166). One spacer (1002) is located proximal to articulation section(1000) while the other spacer (1002) is located distal to articulationsection (1000). It should be understood that spacers (1002) provideisolation of waveguide (166) from inner tube (1020), even througharticulation section (1000) when articulation section (1000) is in anarticulated state. In some versions, spacers (1002) comprise o-rings,though it should be understood that spacers (1002) may take any othersuitable alternative form.

As best seen in FIGS. 22 and 26, a collar (1053) is secured to thedistal end of inner tube (1020). A tongue (1051) projects distally fromcollar (1053). Clamp arm (44) of end effector (40) is pivotally securedto tongue (1051). Clamp (44) arm is thereby secured to inner tube(1020). This coupling between clamp arm (44) and inner tube (1020)permits clamp arm (44) to pivot about an axis that is transverse toinner tube (1020). This coupling between clamp arm (44) and inner tube(1020) also permits clamp arm (44) to rotate relative to inner tube(1020), about the longitudinal axis defined by inner tube (1020).However, the coupling between clamp arm (44) and inner tube (1020)prevents clamp arm (44) from translating relative to inner tube (1020),such that clamp arm (44) will translate with inner tube (1020). Clamparm (44) is also pivotally coupled with a distally projecting tongue(1011) of outer tube (1010). Tongue (1011) is best seen in FIGS. 23 and26.

As noted above, inner tube (1020) may be translated longitudinallyrelative to outer tube (1010). It should therefore be understood thatclamp arm (44) may be pivoted away from blade (160) by advancing innertube (1020) distally relative outer tube (1010); and that clamp arm (44)may be pivoted toward blade (160) by retracting inner tube (1020)proximally relative to outer tube (1010). In some other versions, outertube (1010) is retracted proximally relative to inner tube (1020) inorder to pivot clamp arm (44) away from blade (160); and advanceddistally relative to inner tube (1020) in order to pivot clamp arm (44)toward blade (160).

As also noted above outer tube (1010) may be rotated about inner tube(1020). Since collar (1023) permits rotation of tongue (1021) and clamparm (44) relative to inner tube (1020), it should be understood thatrotation of outer tube (1010) about inner tube (1020) may result inrotation of tongue (1021) and clamp arm (44) about inner tube (1020) andblade (160). Such rotation may be driven by manual rotation of knob (31)and/or using some other feature(s). Since blade (160) remainsrotationally stationary relative to clamp arm (44), rotating clamp arm(44) about blade (160) may enable selective positioning of clamp arm(44) relative to particular geometric features (e.g., multifacetedfaces/edges) of blade (160), which may in turn provide varying effectson tissue engaged by end effector (40). In some versions, waveguide(166) and blade (160) are also rotatable relative to inner tube (1020),which may provide further control over the orientation and configurationof end effector (40).

Two articulation bands (1040, 1042) extend through a gap defined betweenouter tube (1010) and outer tube (1020). The distal ends of articulationbands (1040, 1042) are secured to outer tube (1020). Alternatively,articulation bands (1040, 1042) may be secured to outer tube (1010)(e.g., in versions where inner tube (1020) is translated relative toouter tube (1010) in order to drive clamp arm (44) toward and away fromblade (160)). As with cables (140, 142) described herein, articulationbands (1040, 1042) are operable to translate longitudinally in opposingdirection to articulate articulation section (1000). FIGS. 24-25 show anexample of articulation section (1000) in an articulated state.

In some instances, it may be desirable to rotate outer tube (1010) aboutinner tube (1020) when articulation section (1000) is in an articulatedstate (i.e., when segmented regions (1012, 1022) are in bentconfigurations). Such action of outer tube (1010) may be promoted byusing a configuration of an outer tube (1030) as shown in FIG. 28. Outertube (1030) of this example is substantially similar to outer tube(1010) described above. However, outer tube (1030) of this example has asegmented region (1032) with more segments (1032A, 1032B, 1032C, 1032D)than segmented region (1012).

Like segments (1012A, 1012B), segments (1032A, 1032B, 1032C, 1032D) ofthe example shown in FIG. 28 are joined to each other and to theremainder of outer tube (1030) by coupling features (1033). Each segment(1032A, 1032B, 1032C, 1032D) has a respective pair of coupling features(1033), which provide hinged couplings between segments (1032A, 1032B,1032C, 1032D) and the rest of outer tube (1030). The coupling features(1033) in each pair are angularly offset from each other by 180°.Segments (1032A, 1032B, 1032C, 1032D) are also separated from each otherand from the remainder of outer tube (1030) by gaps (1035). Each segment(1032A, 1032B, 1032C, 1032D) also includes a pair of proximally orientedprojections (1037) traversing respective gaps (1035). The projections(1037) in each pair are angularly offset from each other by 180°. Ineach segment (1032A, 1032B, 1032C, 1032D), the coupling features (1033)are angularly offset from the projections (1037) by 90°, such thatcoupling features (1033) and projections (1037) are alternatingly andevenly positioned along the proximally facing perimeter of each segment(1032A, 1032B, 1032C, 1032D).

Unlike segments (1013A, 1013B), segments (1032A, 1032B, 1032C, 1032D)are angularly offset relative to each other by 90°. Thus, instead ofcoupling features (1033) all being aligned with each other alongsegments (1032A, 1032B, 1032C, 1032D) and projections (1037) all beingaligned with each other along segments (1032A, 1032B, 1032C, 1032D),coupling features (1033) and projections (1037) alternate along segments(1032A, 1032B, 1032C, 1032D). This arrangement allows segmented region(1032) to rotate about segmented region (1022) while segmented regions(1032, 1022) are both in a bent configuration. Of course, thisarrangement also allows segmented region (1032) to flex; and preventssegments (1032A, 1032B, 1032C, 1032D) from rotating relative to eachother. As with the features of segmented region (1012), the features ofsegmented region (1030) may be formed by a laser cutting process and/orany other suitable processes.

FIG. 29 shows yet another exemplary configuration of outer tube (1060)that may be used to provide rotatability of outer tube (1060) aboutinner tube (1020) during an articulated state. Outer tube (1060) of thisexample includes a segmented region (1062) that has a single continuoussegment (1062A) defined by a spiral cut gap (1065). A plurality ofcoupling features (1033) traverse spiral cut gap (1065) in an angularlyalternating fashion. These coupling features (1033) provide hingedcouplings between adjacent portions of segment (1062A). This arrangementallows segmented region (1062) to rotate about segmented region (1022)while segmented regions (1062, 1022) are both in a bent configuration.Of course, this arrangement also allows segmented region (1062) to flex;and prevents portions of segment (1062A) from rotating relative to eachother. As with the features of segmented region (1012), the features ofsegmented region (1060) may be formed by a laser cutting process and/orany other suitable processes.

FIG. 30 shows an exemplary alternative arrangement positioning forarticulation bands (1040, 1042). In this example, articulation bands(1040, 1042) are positioned within inner tube (1020). By way of exampleonly, articulation bands (1040, 1042) may pass through one or morespacers (1002). The distal ends of articulation bands (1040, 1042) maybe secured to inner tube (1020) to provide articulation. FIG. 31 showsyet another merely illustrative example where articulation bands (1040,1042) are omitted in favor of an articulation cable (140), which ispositioned in a gap between inner tube (1020) and outer tube (1010). Thedistal end of articulation cable (140) may be secured to inner tube(1020) to provide articulation. In the examples shown in FIGS. 30-31,end effector (40) may be rotated relative to outer tube (1010) and outersheath (32) via inner tube (1020). Other suitable arrangements andoperabilities will be apparent to those of ordinary skill in the art inview of the teachings herein.

D. Exemplary Articulation Section with Articulation Bands and FlexibleClosure Sleeve

FIGS. 32-34 show a configuration that combines articulation section(900), described above, with a flexible closure sleeve (1070). In thisexample, clamp arm (44) is pivotally coupled with distal flange (942) ofdistal collar (940) by a pin (1073). Flexible closure sleeve (1070) isslidably disposed over articulation section (900) and is pivotallycoupled with clamp arm (44) by another pin (1074). When flexible closuresleeve (1070) is slid distally relative to articulation section (900),flexible closure sleeve (1070) drives clamp arm (44) pivotally towardblade (160) as shown in FIG. 33. When flexible closure sleeve (1070) issubsequently slid proximally relative to articulation section (900),flexible closure sleeve (1070) drives clamp arm (44) pivotally away fromblade (160). Flexible closure sleeve (1070) thus has sufficient columnstrength and tensile to drive clamp arm (44) toward and away from blade(160). However, flexible closure sleeve (1070) also has sufficientflexibility to permit articulation section (900) to articulate,regardless of whether clam arm (44) is in an open or closed position, asshown in FIG. 34. These properties may be provided in flexible closuresleeve (1070) in various ways, including but not limited toconfigurations (e.g., linked sections, ribs, etc.) and/or materialselections (e.g., elastomeric, Teflon coating, etc.). Various suitableways in which closure sleeve (1070) may be formed and configured will beapparent to those of ordinary skill in the art in view of the teachingsherein.

E. Exemplary Linked Articulation Band Mechanism

FIGS. 35A-35C show another exemplary alternative mechanism (1100) thatmay be used in place of articulation cables (140, 142) to laterallydeflect end effector (40) away from the longitudinal axis of shaftassembly (30). Mechanism (1100) of this example comprises anarticulation band (1140) that is configured to translate longitudinallyrelative to shaft assembly (30). Shaft assembly (30) comprises an innertube (1130), which is configured to remain longitudinally stationary asarticulation band (1140) translates longitudinally. Flexible acousticwaveguide (166) is disposed within inner tube (1130) and extendsdistally from inner tube (1130).

Mechanism (1100) of the present example further comprises a pivotinglink (1120). An intermediate portion of pivoting link (1120) isrotatably secured to inner tube (1130) by a pivot (1122), such thatpivoting link (1120) is rotatable relative to inner tube (1130) about anaxis defined by pivot (1122). A distal end of articulation band (1140)is rotatably secured to a first end of pivoting link (1120) via a pin(1123) such that longitudinal translation of articulation band (1140)causes rotation of pivoting link (1120) relative to inner tube (1130)about an axis defined by pivot (1122). Mechanism (1100) furthercomprises a drive lever (1150). A first end of drive lever (1150) isslidably and rotatably secured to a second end of pivoting link (1120)via a slot (154) and pin (1125). A second end of drive lever (1150) isslidably and rotatably coupled to distal flange (136) via a slot (1152)and pin (1156). An intermediate portion of drive lever (1150) isrotatably coupled to proximal flange (138) via a pin (1151). Drive lever(1150) is rotatable relative to proximal flange (138) about an axisdefined by pin (1151).

As shown in FIG. 35B, distal longitudinal movement of articulation band(1140) causes clockwise rotation of pivoting link (1120). Clockwiserotation of pivoting link (1120) will drive the first end of drive lever(1150) laterally away from inner tube (1130). Lateral movement of thefirst end of drive lever (1150) away from inner tube (1130) will drivethe second end of drive lever (1150) and thus distal flange (136)lateral in the opposite direction. This lateral movement of flange (136)will cause deflection of flexible acoustic waveguide (166) and blade(160).

As shown in FIG. 35C, proximal longitudinal movement of articulationband (1140) causes counter-clockwise rotation of pivoting link (1120).Counter-clockwise rotation of pivoting link (1120) will drive the firstend of drive lever (1150) laterally toward inner tube (1130). Lateralmovement of the first end of drive lever (1150) toward inner tube (1130)will drive the second end of drive lever (1150) and thus distal flange(136) lateral in the opposite direction. This lateral movement of flange(136) will cause deflection of flexible acoustic waveguide (166) andblade (160), in a direction opposite to that shown in FIG. 35B.

F. Exemplary Articulation Section with Articulation Bands and RetainingRings

FIGS. 36-42 depict another exemplary articulation section (1300) thatmay be interposed between a shaft assembly (1330) and end effector (40)in place of articulation section (130), to selectively position anultrasonic blade (1360) at various lateral deflection angles relative tothe longitudinal axis defined by shaft assembly (130). Shaft assembly(1330) of this example is substantially identical to shaft assembly (30)described above and includes an outer sheath (1332). While an endeffector (40) with clamp arm (44) is not shown in this example, itshould be understood that articulation section (1300) may be readilyincorporated into an instrument that has an end effector (40) with clamparm (44). Articulation section (1300) of this example comprises a pairof articulation bands (1310, 1314), a set of three retention collars(1320), and a pair of ribbed body portions (1370, 1380). A distal outertube (1336) and a distal collar (1340) are located distal to a bendableregion of articulation section (1300).

Articulation section (1300) of the present example is used with awaveguide (1366) as best seen in FIG. 38. Of course, articulationsection (1300) could alternatively be used with any other suitable kindof waveguide. Waveguide (1366) of this example is substantially similarto waveguide (166) described above. In particular, waveguide (1366)includes a flexible narrowed section (1364) that is longitudinallypositioned between a proximal flange (1390) and a distal flange (1394).Distal flange (1394) is located at a position along the length ofwaveguide (1366) corresponding to a distal-most node associated withresonant ultrasonic vibrations communicated through waveguide (1366).Proximal flange (1390) is located at a position along the length ofwaveguide (1366) corresponding to a second-to-distal-most nodeassociated with resonant ultrasonic vibrations communicated throughwaveguide (1366). Waveguide (1366) may be readily coupled with atransducer assembly such as transducer assembly (12) described above.Transducer assembly (12) may thus generate ultrasonic vibrations thatare transmitted along waveguide (1366) to blade (1360) in accordancewith known configurations and techniques.

Each flange (1390, 1394) includes a respective pair of opposing flats(1392, 1396) in this example. Flats (1392, 1396) are oriented alongvertical planes that are parallel to a vertical plane extending throughnarrowed section (1364) in the present example. Flats (1392, 1396) areconfigured to provide clearance for articulation bands (1310, 1314) asbest seen in FIG. 42. In particular, flats (1392) accommodatearticulation bands (1310, 1314) between proximal flange (1390) and theinner diameter of outer sheath (1332): while flats (1396) accommodatearticulation bands (1310, 1314) between distal flange (1394) and theinner diameter of distal outer tube (1336). Of course, flats (1392,1396) could be substituted with a variety of features, including but notlimited to slots, channels, etc., with any suitable kind of profile(e.g., square, flat, round, etc.). In the present example, flats (1392,1396) are formed in a milling process, though it should be understoodthat any other suitable process(es) may be used. Various suitablealternative configurations and methods of forming flats (1392, 1396)will be apparent to those of ordinary skill in the art in view of theteachings herein. It should also be understood that waveguide (1366) mayinclude flats formed in accordance with at least some of the teachingsof U.S. patent application Ser. No. 13/868,336, entitled “UltrasonicDevice for Cutting and Coagulating,” filed Apr. 23, 2013, the disclosureof which is incorporated by reference herein.

FIG. 39 shows ribbed body portions (1370, 1380) in greater detail. Inthe present example, ribbed body portions (1370, 1380) are formed of aflexible plastic material, though it should be understood that any othersuitable material may be used. Ribbed body portion (1370) comprises aset of three ribs (1372) that are configured to promote lateral flexingof ribbed body portion (1370). Of course, any other suitable number ofribs (1372) may be provided. Ribbed body portion (1370) also defines achannel (1374) that is configured to receive articulation band (1310)while allowing articulation band (1310) to slide relative to ribbed bodyportion (1370). Similarly, ribbed body portion (1380) comprises a set ofthree ribs (1382) that are configured to promote lateral flexing ofribbed body portion (1380). Of course, any other suitable number of ribs(1382) may be provided. Ribbed body portion (1380) also defines achannel (1384) that is configured to receive articulation band (1380)while allowing articulation band (1314) to slide relative to ribbed bodyportion (1380).

As best seen in FIGS. 37 and 42, ribbed body portions (1370, 1380) arelaterally interposed between articulation bands (1310, 1314) andwaveguide (1366). Ribbed body portions (1370, 1380) mate with each othersuch that they together define an internal passage sized to accommodatewaveguide (1366) without contacting waveguide (1366). In addition, whenribbed body portions (1370, 1380) are coupled together, a pair ofcomplementary distal notches (1376, 1386) formed in ribbed body portions(1370, 1380) align to receive an inwardly projecting tab (1338) ofdistal outer tube (1336). This engagement between tab (1338) and notches(1376, 1386) longitudinally secures ribbed body portions (1370, 1380)relative to distal outer tube (1336). Similarly, when ribbed bodyportions (1370, 1380) are coupled together, a pair of complementaryproximal notches (1378, 1388) formed in ribbed body portions (1370,1380) align to receive an inwardly projecting tab (1334) of outer sheath(1332). This engagement between tab (1334) and notches (1378, 1388)longitudinally secures ribbed body portions (1370, 1380) relative toouter sheath (1332). Of course, any other suitable kinds of features maybe used to couple ribbed body portions (1370, 1380) with outer sheath(1332) and/or distal outer tube (1336).

In the present example, outer rings (1320) are located at longitudinalpositions corresponding to ribs (1372, 1382), such that three rings(1320) are provided for three ribs (1372, 1382). Articulation band(1310) is laterally interposed between rings (1320) and ribbed bodyportion (1370); while articulation band (1314) is laterally interposedbetween rings (1320) and ribbed body portion (1380). Rings (1320) areconfigured to keep articulation bands (1310, 1314) in a parallelrelationship, particularly when articulation section (1300) is in a bentconfiguration (e.g., similar to the configuration shown in FIG. 20B). Inother words, when articulation band (1310) is on the inner diameter of acurved configuration presented by a bent articulation section (1300),rings (1320) may retain articulation band (1310) such that articulationband (1310) follows a curved path that complements the curved pathfollowed by articulation band (1314). It should be understood thatchannels (1374, 1378) are sized to accommodate respective articulationbands (1310, 1314) in such a way that articulation bands (1310, 1314)may still freely slide through articulation section (1300), even withrings (1320) being secured to ribbed body portions (1370, 1380). Itshould also be understood that rings (1320) may be secured to ribbedbody portions (1370, 1380) in various ways, including but not limited tointerference fitting, adhesives, welding, etc.

FIG. 40 shows distal collar (1340) in greater detail. Distal collar(1340) includes a distal flange (1342), a pair of outwardly extendingprojections (1344), a pair of lateral recesses (1346), and a convexlytapering inner surface (1348). Distal flange (1342) is configured toengage the distal edge of distal outer tube (1336), such that distalflange (1342) mechanically grounds distal collar (1340) against distalouter tube (1336). Outwardly extending projections (1344) are configuredto fit in respective distal openings (1311, 1315) of articulation bands(1310, 1314). Articulation bands (1310, 1314) are thus secured to distalcollar (1340) via projections (1344). Lateral recesses (1346)accommodate respective portions of articulation bands (1310, 1314) thatare adjacent to distal openings (1311, 1315). It should also beunderstood that articulation bands (1310, 1314) also include proximalopenings (1313, 1317) that are used to couple articulation bands (1310,1314) with articulation drive features that are operable to translatearticulation bands (1310, 1314) longitudinally in an opposing fashion,as taught above.

Articulation section (1300) of this example operates substantiallysimilar to articulation section (900) described above. When articulationbands (1310, 1314) are translated longitudinally in an opposing fashion,a moment is created and applied to nodal distal flange (1394) throughdistal outer tube (1336). This causes articulation section (1300) andnarrowed section (1364) of waveguide (1366) to articulate, withouttransferring axial forces in articulation bands (1310, 1314) towaveguide (1366). In particular, as best seen in FIG. 42, articulationsection (1300) of the present example maintains a gap (1345) between theproximal end of distal collar (1340) and nodal distal flange (1394) ofwaveguide (1366), such that collar (1340) does not bear proximallyagainst a distally facing surface of distal flange (1394), even whenarticulation section (1300) is in a bent state. Thus, nodal distalflange (1394) only receives laterally directed bearing forces (by distalouter tube (1336) and/or bands (1310, 1314)) when being driven to anarticulated position.

It should be understood that one articulation band (1310, 1314) may beactively driven distally while the other articulation band (1310, 1314)is passively permitted to retract proximally. As another merelyillustrative example, one articulation band (1310, 1314) may be activelydriven proximally while the other articulation band (1310, 1314) ispassively permitted to advance distally. As yet another merelyillustrative example, one articulation band (1310, 1314) may be activelydriven distally while the other articulation band (1310, 1314) isactively driven proximally. Various suitable ways in which articulationbands (1310, 1314) may be driven will be apparent to those of ordinaryskill in the art in view of the teachings herein.

In the discussion of the examples shown in FIGS. 18A-18B, it was notedhow boss surfaces (822) of ribbed body (810) engage each other whenribbed body (810) is bent to the configuration shown in FIG. 18A, suchthat boss surfaces (822) provide a hard stop that restricts the bendangle of articulation section (800). The same principle may apply toarticulation section (1300) shown in FIGS. 36-42. In particular, ribs(1372, 1382) of the present example may include opposing surfaces thatact as boss surfaces that engage each other on one side of articulationsection (1300) when articulation section (1300) reaches a fullyarticulated state. Such surfaces may thus restrict the bend angle ofarticulation section (1300) (e.g., to prevent narrowed section (1364) ofwaveguide (1366) from overbending, etc.). In addition or in thealternative, rings (1320) may eventually contact each other duringarticulation to restrict the bend angle of articulation section (1300).Other suitable ways in which the bend angle of articulation section(1300) may be restricted will be apparent to those of ordinary skill inthe art in view of the teachings herein.

While articulation bands (1310, 1314) are secured to distal collar(1340) in the present example, it should be understood that articulationbands (1310, 1314) may instead be secured directly to respective lateralsides of nodal distal flange (1394). It should also be understood that,when articulation bands (1310, 1314) are translated in an opposingfashion in such versions, articulation section (1300) may bend as taughtelsewhere herein. Distal collar (1340) may thus be eliminated, ifdesired. Furthermore, distal outer tube (1336) may be eliminated in suchversions, if desired. Still other suitable variations of articulationsection (1300) will be apparent to those of ordinary skill in the art inview of the teachings herein.

V. Exemplary Alternative Shaft Assembly

In any of the foregoing examples, shaft assembly (30) may be provided ina modular form, such that a distal portion of shaft assembly (30) isremovable from a proximal portion of shaft assembly (30). By way ofexample only, this may permit re-use of the proximal portion of shaftassembly (30) and handle assembly (20) while the distal portion of shaftassembly (30) is disposed of after use. As another merely illustrativeexample, various kinds of end effectors (40) may be used with the samehandle assembly (20) when a distal portion of shaft assembly (30) isremovable from a proximal portion of shaft assembly (30). Other kinds ofscenarios in which it may be desirable to provide removability of adistal portion of shaft assembly (30) from a proximal portion of shaftassembly (30) will be apparent to those of ordinary skill in the art inview of the teachings herein. The following provides one merelyillustrative example of a way in which a distal portion of shaftassembly (30) may be removable from a proximal portion of shaft assembly(30). Various suitable ways in which the following teachings may becombined with the above teachings will be apparent to those of ordinaryskill in the art in view of the teachings herein. Similarly, variousother suitable ways in which distal portion of shaft assembly (30) maybe removable from a proximal portion of shaft assembly (30) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

FIGS. 43A-44B show an exemplary alternative shaft assembly (1200). Shaftassembly (1200) is configured to operate substantially similar to shaftassembly (30) discussed above except for the differences discussedbelow. Shaft assembly (1200) comprises a reusable proximal section(1210) and a disposable distal section (1220). Proximal section (1210)and distal section (1220) of shaft assembly (1200) each include an outersheath (1232A, 1232B) that encloses the drive features and the acoustictransmission features discussed above with respect to instrument (10).Proximal section (1210) of shaft assembly (1200) extends distally fromhandle assembly (20). A distal end of proximal section (1210) terminatesin a connection portion (1212) that will be discussed in more detailbelow. Articulation section (130) is located at a distal end of distalsection (1220) of shaft assembly (1200), with end effector (40) beinglocated distal to articulation section (130). A proximal end of distalsection (1220) comprises a connection portion (1222) that will bediscussed in more detail below.

Connection portion (1212) comprises a bayonet pin (1214) configured tocouple with a mating bayonet slot (1224) of connection portion (1222) tothereby provide coupling between proximal section (1210) and distalsection (1220). In particular, bayonet features (1214, 1224) securesections (1210, 1220) together after pin (1214) is first insertedlongitudinally in slot (1224) and is then rotated in slot (1224). Whilebayonet features (1214, 1224) provide coupling between proximal section(1210) and distal section (1220) in the present example, it should beunderstood that any other suitable type of coupling may be used.

A pair of articulation bands (1240, 1242) extend through proximalsection (1210) and distal section (1220). Articulation bands (1240,1242) each comprise reusable portions (1240A, 1242A) and disposableportions (1240B, 1242B). As best seen in FIGS. 43A and 44A, distal endsof reusable portions (1240A, 1242A) of articulation bands (1240, 1242)extend distally from connection portion (1212). Distal ends of reusableportions (1240A, 1242A) each present a first mating feature (1244,1246). Proximal ends of disposable portions (1240B, 1242B) ofarticulation bands (1240, 1242) extend proximally from connectionportion (1222). Proximal ends of disposable portions (1240B, 1242B) eachpresent a second mating feature (1248, 1250). Second mating features(1248, 1250) are configured to engage with respective first matingfeatures (1244, 1246) when proximal section (1210) and distal section(1220) are coupled together as shown in FIGS. 43B and 44B. Matingfeatures (1244, 1246, 1248, 1250) allow for longitudinal movement ofreusable portions (1240A, 1242A) of articulation bands (1240, 1242) tobe communicated to disposable portions (1240B, 1242B) of articulationbands (1240, 1242). In other words, portions (1240A, 1240B) willtranslate unitarily when mating features (1244, 1248) are coupledtogether; and portions (1242A, 1242B) will translate unitarily whenmating features (1248, 1250) are coupled together. Various othersuitable ways in which portions of articulation bands (1240, 1242) maybe selectively coupled together will be apparent to those of ordinaryskill in the art in view of the teachings herein. Similarly, variousother suitable ways in which other portions of shaft assembly (30) maybe selectively coupled together will be apparent to those of ordinaryskill in the art in view of the teachings herein.

VI. Miscellaneous

It should be understood that any of the versions of instrumentsdescribed herein may include various other features in addition to or inlieu of those described above. By way of example only, any of theinstruments described herein may also include one or more of the variousfeatures disclosed in any of the various references that areincorporated by reference herein. It should also be understood that theteachings herein may be readily applied to any of the instrumentsdescribed in any of the other references cited herein, such that theteachings herein may be readily combined with the teachings of any ofthe references cited herein in numerous ways. Moreover, those ofordinary skill in the art will recognize that various teachings hereinmay be readily applied to electrosurgical instruments, staplinginstruments, and other kinds of surgical instruments. Other types ofinstruments into which the teachings herein may be incorporated will beapparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.Similarly, those of ordinary skill in the art will recognize thatvarious teachings herein may be readily combined with various teachingsof U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” published Aug. 31, 2004,the disclosure of which is incorporated by reference herein.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

I/We claim:
 1. An apparatus for operating on tissue, the apparatuscomprising: (a) a body; (b) an ultrasonic transducer; (c) a shaftextending distally from the body, wherein the shaft defines alongitudinal axis; (d) an acoustic waveguide, wherein the waveguide isacoustically coupled with the transducer, wherein the waveguidecomprises a flexible portion and a nodal portion located distal to theflexible portion; (e) an articulation section coupled with the shaft,wherein a portion of the articulation section encompasses the flexibleportion of the waveguide, wherein the articulation section furtherincludes a collar located distal to the nodal portion of the waveguide;(f) an end effector comprising an ultrasonic blade in acousticcommunication with the waveguide; and (g) an articulation drive assemblyoperable to drive articulation of the articulation section to therebydeflect the end effector from the longitudinal axis, wherein thearticulation drive assembly comprises at least one translatingarticulation driver coupled with the collar.
 2. The apparatus of claim1, wherein the articulation section further comprises an outer tubeengaged with the collar, wherein a portion of the translating member isinterposed between the outer tube and the nodal portion of thewaveguide.
 3. The apparatus of claim 1, wherein the waveguide includesat least one flat lateral region, wherein the at least one translatingarticulation driver extends along the at least one flat lateral region.4. The apparatus of claim 1, wherein the articulation section comprisesa set of ribs separated by gaps configured to promote flexing of thearticulation section, wherein the ribs include surfaces positioned toengage each other in response to the articulation section reaching afully articulated state, such that the engaged surfaces of the ribs areconfigured to restrict a bend angle of the articulation section in thefully articulated state
 5. The apparatus of claim 1, wherein thearticulation section comprises a set of ribs separated by gapsconfigured to promote flexing of the articulation section, wherein thearticulation section further comprises a set of rings associated withthe set of ribs, wherein the at least one translating member islaterally interposed between the set of rings and the set of ribs. 6.The apparatus of claim 1, wherein the articulation drive assemblycomprises at least one rotating member, wherein the rotating member isconfigured to rotate to thereby cause articulation of the articulationsection.
 7. The apparatus of claim 6, further comprising a firsttranslating articulation driver and a second translating articulationdriver, wherein the first and second translating articulation driversare translatable to cause articulation of the articulation section,wherein the first translating articulation driver and the secondtranslating articulation driver are coupled with the at least onerotating member, wherein the first translating articulation driver andthe second translating articulation driver are coupled with the at leastone rotating member on opposite sides of an axis of rotation of the atleast one rotating member.
 8. The apparatus of claim 6, furthercomprising a first translating articulation driver and a secondtranslating articulation driver, wherein the first and secondtranslating articulation drivers are translatable to cause articulationof the articulation section, wherein the at least one rotating membercomprises a pinion, wherein the articulation drive assembly furthercomprises a first rack member and a second rack member mechanicallyengaged with the pinion on opposite sides of the pinion, wherein thefirst rack member is secured to the first translating articulationdriver, wherein the second rack member is secured to the secondtranslating articulation driver.
 9. The apparatus of claim 6, whereinthe at least one rotating member comprises a plurality of teeth disposedabout an exterior circumference of the at least one rotating member,wherein the articulation drive assembly further comprises at least onerack member, wherein the at least one rack member comprises a pluralityof teeth engaged with the teeth of the at least one rotating member,wherein the at least one rack member is operable to rotate the at leastone rotating member.
 10. The apparatus of claim 6, wherein the at leastone rotating member comprises a first threaded region and a secondthreaded region, wherein the first threaded region and the secondthreaded region comprise threads having opposite thread pitches.
 11. Theapparatus of claim 10, wherein the articulation drive assembly furthercomprises a first threaded member and a second threaded member, whereinthe first threaded member is configured to mate with the first threadedregion of the at least one rotating member, wherein the second threadedmember is configured to mate with the second threaded region of the atleast one rotating member, wherein the least one rotating member isrotatable in a single direction to cause simultaneous longitudinaltranslation of the first threaded member in a first direction andsimultaneous longitudinal translation of the second threaded member in asecond direction.
 12. The apparatus of claim 11, further comprising afirst translating articulation driver and a second translatingarticulation driver, wherein the first and second translatingarticulation drivers are translatable to cause articulation of thearticulation section, wherein the first threaded member is operable todrive the first translating articulation driver, wherein the secondthreaded member is operable to drive the second translating articulationdriver.
 13. The apparatus of claim 6, wherein the articulation driveassembly further comprises a locking feature, wherein the lockingfeature is operable to move from a first position to a second position,wherein the locking feature is configured to prevent rotation of the atleast one rotating member when the locking feature is in the firstposition, and wherein the locking feature is configured to permitrotation of the at least one rotating member when the locking feature isin the second position.
 14. The apparatus of claim 6, wherein the atleast one rotating member comprises a first rotating member and a secondrotating member, wherein the first rotating member is configured torotate to thereby cause articulation of the articulation section, andwherein the second rotating member is configured to rotate to therebycause rotation of the shaft.
 15. The apparatus of claim 14, furthercomprising a sliding rotation knob, wherein the rotation knob isoperable to slide between a first longitudinal position and a secondlongitudinal position, wherein the rotation knob is configured tomechanically engage the first rotating member and thereby rotate thefirst rotating member when the rotation knob is in the firstlongitudinal position, wherein the rotation knob is configured tomechanically engage the second rotating member and thereby rotate thesecond rotating member when the rotation knob is in the secondlongitudinal position.
 16. The apparatus of claim 6, wherein thearticulation drive assembly further comprises a motor, wherein the motoris configured to rotate the at least one rotating member.
 17. Theapparatus of claim 1, wherein the shaft comprises a first portion and asecond portion, wherein at least a first translating articulation driverextends through the first portion of the shaft, wherein at least asecond translating articulation driver extends through the secondportion of the shaft, wherein the first section of the shaft isconfigured to couple with the second section of the shaft, and whereinthe at least a first translating articulation driver is configured tomechanically engage the at least a second translating articulationdriver when the first section of the shaft is coupled with the secondsection of the shaft.
 18. An apparatus for operating on tissue, theapparatus comprising: (a) a body; (b) an ultrasonic transducer operableto convert electrical power into ultrasonic vibrations; (c) a shaftextending distally from the body, wherein the shaft defines alongitudinal axis; (d) an articulation section coupled with the shaft;(e) an end effector coupled with the articulation section, wherein theend effector comprises an ultrasonic blade in acoustic communicationwith the ultrasonic transducer via a waveguide; and (f) an articulationdrive assembly operable to drive articulation of the articulationsection to thereby deflect the end effector from the longitudinal axis,wherein a portion of the waveguide is configured to bend with thearticulation section, wherein the articulation drive assembly comprises:(i) at least one rotating member, and (ii) at least one elongate member,wherein the at least one rotating member is rotatably coupled with theat least one elongate member, wherein the rotating member is configuredto rotate as the elongate member translates longitudinally, and whereinthe elongate member is operable to translate longitudinally to therebycause articulation of the articulation section.
 19. An apparatus foroperating on tissue, the apparatus comprising: (a) a body; (b) anultrasonic transducer operable to convert electrical power intoultrasonic vibrations; (c) a shaft extending distally from the body,wherein the shaft defines a longitudinal axis; (d) an articulationsection coupled with the shaft, wherein the articulation sectioncomprises: (i) an outer tube comprising a plurality of outer tubesegments, wherein the outer tube segments are coupled together via aplurality of tabs and recesses, wherein the outer tube segments provideflexibility to the outer tube, and (ii) an inner tube comprising aplurality of inner tube segments, wherein the inner tube segments arecoupled together via a plurality of tabs and recesses, wherein the innertube segments provide flexibility to the outer tube; and (e) an endeffector coupled with the articulation section, wherein the end effectorcomprises an ultrasonic blade in acoustic communication with theultrasonic transducer via a waveguide.
 20. The apparatus of claim 19,wherein the outer tube is configured to rotate about the inner tube whenthe inner tube and outer tube are both in an articulated state.